Nuclear Thresholds is a temporary architectural installation at the location of the original Chicago Pile-1, marked for the last fifty years by Henry Moore's Nuclear Energy sculpture. Based on computational modeling of unstable processes, the installation creates a material threshold around Nuclear Energy that resonates at radically different scales. It invites visitors to interact physically with the shape and patterns of criticality that drove the experiment, provoking deep questions about the scientific, historical, and existential thresholds CP-1 crossed.

This commission is made possible by the University's Public Art Committee.

Architects' Statement

Nuclear Thresholds commemorates the 75th anniversary of Enrico Fermi’s “Chicago Pile–1”—the first man-made, self-sustaining nuclear chain reaction. The project brief invited us to both reflect on the nature of the experiment, as well as the tension between control and the loss of control engendered by the birth of the Nuclear Age. Essentially, the project is a protean pile of material that begins as a simple arc and then dissolves into exponential complexity.

In developing the project, we thought about chain reactions, and the random walks of liberated neutrons. We thought about critical mass, when a chain reaction is barely self-sustaining, and supercriticality, the turning point when the rate of fission increases, sometimes to the point of being out of control. We were interested in the complex materiality embodied in the original experiment: the tightly-packed pile of graphite used for the experiment, as well as thinking about matter as something not solid but composed largely of space and energetic particles. The incongruous siting of this existentially pivotal experiment in a squash court captured our imaginations. Finally, we also wanted to pay homage to the Henry Moore sculpture by intensifying the site and partially enframing it on its vast plinth.

The installation consists of 241 two-inch diameter, seventy-five-foot-long cords of EPDM rubber. The cords are close-packed in a hexagonal array, forming a simple arc that serves as a bench. The bench invites contemplation and directs focus to the Henry Moore Nuclear Energy sculpture in the center of the plinth. After forming a quarter of circle, the form splits into two branches that explode the regular, controlled form of the arc. Those two branches then each twist and split into two more branches, and so on, exponentially increasing the complexity of the overall form until all the cords are writhing freely.

I think there are a lot of different ways into thinking about the installation, and hopefully visitors will pick up some reference that interests them and pulls them into deeper contemplation. It’s something of a puzzle, and is intended to provoke questioning of some of the assumptions we have about the physical world and our role within it.